The X-box Factor
Factoring Trinomials
X-Box
PRODUCT
SUM
X-BOX factoring
• This is a guaranteed method for
factoring quadratic equations – no
guessing necessary!
• Background Knowledge needed:
• Dividing a polynomial by a monomial
using the box method (we did this
last lesson)
Factor the X-Box Way
Example: factor
(1)(8)=
8
2
x  6x  8
x
2
x
x
4
4x
4
6
Answer:
2
(x + 2) (x + 4)
2
2x
8
Factor the X-Box Way
product of the
First and Last
Coefficient
(1)(8)=
8
2
4
6
The middle term
x
First Term
x
x
4
4x
2
2
Side of your X
2x
8
Last Term
Side of your X
x  10 x  16
2
x  x  12
2
x  7 x  18
2
x  11 x  24
2
c  3c  2
2
n  13 n  48
2
a  8 a  15
2
Homework
• Worksheet: F:\2nd semester\Algebra
1\chapter 9\13.5 (2).pdf